Winding drum for railway car hand brakes



y 23, 1933. R. w. BURNETT 1,911,057

WINDING'DRUM FOR RAILWAY CAR HANIS BRAKES Original Filed Oct. 31, 1927 2 Sheets-Sheet 1 IIIIIIIIIIIIIIIIIIIIII/I {L lAMAYl/Q A ,,,,,,IInnnnn z r a May 23, 1933. R w BURNETT 1,911,057

WINDING DRUM FOR RAILWAY CAR HAND BRAKES Original i e 1927 2 Sheets-Sheet 2 Patented May 23, 1933 PATENT OFFICE RICHARD W. BURNETT, OF CHICAGO, ILLINOIS WINDING DRUM FOR RAILWAY GAR HAND BRAKES Original application fi led October 31, 1927, Serial No. 229,967, new Patent No. 1,879,973, dated September 27, 1932. Divided and this application filed March 25, 1929.

My invention relates to operating mechanism for railway car hand brakes and particularly to operating mechanism including a drum for applying power to the brakes and which is operated by means of intermeshing gears.

The principal object of the invention is to provide a simplified construction of winding drum and its associated gear whereby the operating mechanism as a whole may be easily assembled and consequently economically manufactured.

The present invention relates particularly to the provision of a combined winding drum and gear suitable for use in brake operating mechanism of the character shown and described in my copending application, Serial No. 229,967, filed October 31, 1927, which is now Patent No. 1,879,973, dated Sept. 27, 1932, of which the present application is a division. While the specific embodiment herein shown is particularly suitable for the type of winding mechanism disclosed in my said copending application, it is not limited in its uses to the particular type of brake mechanism shown, or to the specific contour of the winding drum except insofar as the appended claims contain express limitations. One of the important and specific objects of the invention is to provide a combined winding drum and gear which will be economical to manufacture and which may be made relatively light without sacrificing the strength required to resist the severe shocks and rough usage to which it will be subjected when in service.

A further specific object of the" invention is to form an integral gear and winding drum in which the winding surface of the drum is formed with a suitable contour to vary the application of power and thereby cooperate with other parts of the brake mechanism.

, However, I do not claim herein, apart from the specific constructions appearing in the claims, the provision of an eccentric winding drum or its combination with other devices for increasing the application of power,

nor do I claim herein broadly the combination of such drum with a short gear train 5 for operatively connecting the drum with the Serial No. 349,818.

bined gear and winding drum form a part.

Fig. 2 is a vertical section taken through the winding mechanism shown in Fig. 1 but illustrating the winding drum in a position which it assumes when the brakes are released.

The brake operating mechanism, of which my combined gear and drum form a part, may be described generally as follows: 10 designates a housing adapted to be secured to the wall of a car. It is made preferably of a back plate 11 and a dished front member 12 which, when attached together provide a rigid support for the various operating parts of the winding mechanism. A power shaft 13 is journaled in suitable bearings in the front and back members of the housin and is provided with .a combined pinion an ratchet gear; the pinion being designated by the reference numeral 14 and the gear being designated by the reference numeral 15. A suitable hand wheel is'secured on the portion of the shaft 13 which projects out of the front member of the housing. A holding pawl 16 is formed with trunnions 17 j ournaled in the housing in a position so that the holding pawl will engage with the teeth of the ratchet gear 15 to prevent reverse movement. A releasing lever 18 is secured to a cam shaft 19, the latter of which is provided with a cam member 20. In one position of the lever 18 the cam member 20 bears down on the holding pawl 16 to hold it in engagement with the ratchet teeth. In another position of the said releasing lever the end 20" of the cam 20 engages the pawl 16 to lift it out of drum 21, the construction of which constitutes the main subject matter of the present invention.

The combined gear and drum 21 consists preferably of a hub portion 22 which is rotatably supported on a shaft 23, permanently lubricated bushings 24 being positioned between the said hub and shaft. The hub portion of the unit 21 is formed at one end with a gear wheel comprising spokes 22*, the rim 23 and gear teeth 24, the latter of which are tapered reversely to the taper of the teeth of the pinion 14. This construction of the gear and pinion makes for ease in operation in that the reversely tapered intermeshing teeth tend to shift the pinion and the gear toward opposite sides of the housing. Such lateral force on the gear, it will be observed, is in opposition to the force exerted by the pulls on the chain at one side of the gear which tend to shift the gear and drum toward the front of the housing. The reversely tapered teeth of the pinion and gear present the further advantage in that they make it practicable to use cast unfinished gears and at the same time obtain the same freedom and smoothness of operation that would be had if finished gears were used, the reverse taper of the teeth serving to shift the pinion and gear laterally to clear any imperfections in the rough casting. The other end of the hub is formed with a channeled winding drum 25, the channel 26 of which is formed to receive certain links of a chain 27, the upper link 27 of which is attached to the winding drum by means of a rivet 28. When the chain is wound about the drum, certain links extend into the channel 26 and certain other links bear. upon the periphery of the drum asfshow I'i in Fig. 1 of the drawings. The periphery- 'of the winding drum is designated generally by the reference character 29 and is formed at one side of the channel 26 with a lateral flange 31 with which the central or spoke portion 22 of the gear is united (Fig. 2). With the above construction of drum, a space intervenes between the lateral flange 31 and the hub portion 22. Suitable reinforcements, preferably in the form of ribs 30, extend across said space at the juncture of the spoke portion 22 ofthe gear with the periphery of the drum.

Insofar as the idea of providing a combined gear and winding drum is concerned, the winding surface may be of any suitable contour. However, in the present embodiment, I preferably form the drum with five winding surfaces designated respectively a, b, a, (l, and e, and also form the drum eccentric to the axis of rotation. The surfaces a, b, c and d ofthe drum are each formed with a convex contour, the curvature being of a relatively large radius, and are so curved at their junction with each other as to avoid sharp corners. This construction relieves the links of the chain which bear upon the periphery of the drum from severe bending strains and also avoids abrupt bending of the end portions of such links that, due to the stretch of the chain or other causes, may project over the corner or junction of adjacent winding surfaces. The hole for the rivet 28 may be formed in any suitable position relative to the axis of rotation. In the present embodiment the rivet hole is so positioned that the upper link 27 of the chain may be attached at a location remote to the axis of rotation and consequently give a quick take-up of the chain during the initial rotation of the drum from the position shown in Fig. 21

A clockwise movement of the hand wheel imparts movement to the winding drum in the direction indicated by the arrow in Fig. 1. When the drum is in its initial released position shown in Fig. 2, the chain is wound about the surface a. during the initial operation of the drum. This winding surface is so formed that the center of the chain, during the rotation of the drum moves inwardly toward the axis of rotation of the drum. The winding surface 6 is preferably located the nearest to the axis of rotation so that immediately after the quick take-up of slack of the chain maximum force is applied to the winding operation. The surfaces 0, (l, and e present gradually increasing winding surfaces. With this form of winding drum maximum take-up and application of power to the brakes can be obtained in less than one complete revolution of the winding drum and thereby permits the winding drum to be formed with a single winding groove, that is to say, a winding groove formed in a single plane in contradistinction to the spiral orm.

The holding and releasing mechanism herein shown and the combination of such mechanism with the vertical hand wheel are merely examples of devices and arrangements for operating the winding mechanism and for holding the same against reverse movement. The specific construction of such holding and releasing mechanism and its combination with the hand wheel form no part of the invention claimed herein, said holding and releasing mechanism being claimed in my said parent application Serial No. 229,967,

filed October 31, 1927, now issued as Patent 1,879,973 dated Sept. 27, 1932, and the combination of said holding and releasing mechanism with the hand wheel being claimed in my copending application Serial No. 281,088, filed May 28, 1928.

I claim:

1. A brake operating mechanism including a flexible member, a combined gear and winding drum comprising a hub portion, a channeled portion united with the hub and providing two spaced webs formed with lateral flanges spaced from a.portion of the hub and providing peripheral winding surfaces about which said flexible member 1s adapted 5 to be wound, and means for attaching said flexible member to the drum at a point between said spaced webs; the said gear member being formed with a toothed rim and with a central web portion, the latter of which is folmed integrally with one of said lateral flanges.

2. A brake 0 crating mechanism including a chain, a com ined gear and winding unit comprisin a hub, a winding drum formed at one en of the hub having a circumferential channel to receive alternate links of said chain and formed with a peripheral flange spaced from the hub on which the intervenin links bear, a gear formed with a rim provi ed with teeth and with a central portion formed integral with the peripheral flange of said drum, and reinforcing ribs in the space between the said peripheral flange and the hub.

3. In a hand brake operatin' mechanism including a chain, a winding rum formed with a series of convex winding surfaces dis posed at an angle to each other and eccentric to the axis of rotation of the drum and about which said chainis adapted to be wound successively.

4. In a hand brake operating mechanism including a chain, a winding drum formed with a central channel to receive alternate links of said chain and provided with a series of peripheral winding surfaces convex in contour and disposed at an angle to each other and eccentric to the axis of rotation of the drum upon which bear the links of the chain between the alternate links above mentioned.

5. In a hand brake operatin mechanism including a chain, a winding rum formed with a central channel to receive alternate links of said chain and provided on its periphery with a series of convex winding surfaces each formed with a relatively large radius, disposed at an angle to each other and eccentric to the axis of rotation of the drum upon which bear the links of the chain between the alternate links above mentioned.

6. A brake operating mechanism including a chain, a combined gear and winding drum comprising a hub, a winding surface formed at one end of the hub havln a circumferential channel to receive afiernate links of said chain and formed with a peripheral flange spaced from the hub on which the intervening links bear, a gear formed with its central portion integral with the eripheral flange of said drum and rein orcmg means positioned in the space between said peripheral flange and hub to unite said flange and the central rtion of the gear with a portion of the hu? 7. In mechanism of the class described, the combination of a brake chain composed of links standing alternately in right angle relation to one another, a hand operated power shaft and pinion, a combined integrally formed reducing gear wheel and drum, the gear portion comprising a web and a circular rim having gear teeth in mesh with the pinion, and the drum portion being in the form of a lateral extension from the web and in part constituting the hub of the wheel portion and being eccentrica-lly elon ated and of ovate formation, the web being offset throughout the area contiguous to said eccentrically elongated portion to brin its inner face outside of the plane of the inner face of the remaining portion of the web, and the drum portion having a chain guide-channel extending around its periphery, said channel being relatively deeply cut back from the tip end of said elongated portion and of a width not substantially greater than the thickness of the terminal link of the chain and adapted to receive the end of said link when standing edgewise, said channel being extended at the same wldth around the remainder of the drum subject to contact of the chain, but at a lesser depth suflicient only to receive the edges of the links standing in edgewise relation to the drum, the portion of the drum behind the extension being broad enough to furnish a rounded surface for the flatwise contact of alternate links of the chain standing with the edges of the intervening links lying edgewise within the groove, and a cross pin extending through the terminal link of said chain and through the extension and the offset portion of the web behind said extension.

8. A brake operating mechanism comprismg a chain, a windingdrum for said chain, a gear having a fixed relation to said drum and formed with tapered teeth, and a driving pinion meshing with said ear and provided with teeth tapered reverse y to the taper of the teeth of said gear.

9. A brake operating mechanism comprising a chain, a winding drum for said chain, a gear integral with one side of the drum and having a rim provided with tapered teeth, and a driving pinion meshing with said gear and provided with teeth tapered reversely to the taper of the teeth of said gear.

DISCLAIMER 1,9l1,057.-Richard W. Burnett, Chicago, Ill WINDING DRUM FOR RAILWAY CAR HAND BRAKES. Patont dated May 23, 1933. Disclaimer filed April 12, 1943, by Marie (7. Burnett, exvcutrix of the estate of Richard W. Burnett. Hereby enters this disclaimer to claims 3, 4, and 5 in said specification.

[Official Gazette [Way 25, 1943.] 

